Moisture Retention Seal

ABSTRACT

Provided is a moisture retention seal for use with a package. The moisture retention seal includes an opened-ended canister having a plurality of canister sealing surfaces. Snap-fitted with spatial interference to the canister at its opened-end, is a moisture retention closure having a plurality of closure sealing surfaces. Each canister sealing surface cooperates with a corresponding one of the closure sealing surfaces to form a plurality of partial seals. At least one of the partial seals includes a micro-bead surface comprising one or more small, inwardly directed, narrowly spaced-apart, micro-bead elements. The package that includes a moisture retention seal of the present invention employs only molded parts and does not require gaskets or secondary seals.

PRIORITY

This patent application claims is a continuation patent application ofU.S. patent application Ser. No. 11/212,111, filed Aug. 25, 2005entitled, “Moisture Retention Seal,” assigned attorney docket number2965/104, and naming Christopher T. Evans, Christopher Gieda, KristenSpeck, and Jose Arevalo as inventors, the disclosure of which isincorporated herein, in its entirety, by reference.

FIELD OF THE INVENTION

The present invention relates to fluid seals. More particularly, thepresent invention relates to a moisture retention seal for plasticpackages.

BACKGROUND OF THE INVENTION

FIG. 1A is an exploded side view of a prior art package 100 thatincluded a cylindrically-shaped prior art canister 102 and a cup-shapedprior art closure 104, which was assembled telescopically over theopened-end of prior art canister 102. Prior art closure 104 has aninside diameter that is somewhat smaller than the outside diameter ofprior art canister 102. Prior art canister 102 and prior art closure104, when assembled as shown in dotted line, combined and cooperated toform a prior art seal 106 (FIG. 1B). Prior art canister 102 included abottom 108, generally configured as a disk, and a sidewall 110,generally configured as a cylindrical surface, coupled to and extendingupwardly from the peripheral edge of bottom 108. Prior art canister 102included an opened-end portion 112 defining an opening 129 for accessfrom the top of prior art canister 102 to material or objects containedtherein. Typically, prior art canister 102 was formed integrally, by,for example, blow-molding or injection-molding of thermoplasticmaterial.

Prior art closure 104 included a top 114, generally configured as adisk, and a skirt 116, generally configured as an annular ring, coupledto and depending downwardly from the peripheral edge of top 114. Top 114defined an aperture 118 (FIG. 1B) therethrough for extracting materialor objects contained in prior art canister 102 from its opened-endportion 112 after assembly of prior art canister 102 and prior artclosure 104. Often, prior art package 100 further included an aperturelid 120 to close off aperture 118 of prior art closure 104. In oneembodiment, aperture lid 120 was coupled to prior art closure 104 by aliving hinge 122, by which aperture lid 120 pivoted with respect toprior art closure 104 to close off aperture 118 of prior art closure104. Typically, prior art closure 104 was also formed integrally, by,for example, blow-molding or injection-molding of thermoplasticmaterial. To form a seal between aperture lid 120 and closure 104,aperture lid 120 was typically snap-fitted to closure 104 in a mannerwell known to one of ordinary skill in the art. Aperture lid 120included a lid sealing ring 132 near the outer peripheral edge on thebottom surface of aperture lid 120. Lid sealing ring 132 mated with aclosure sealing ring 134 formed on the top surface of closure 104 whenaperture lid 120 was pivoted, snap-fitted, and placed in a closedrelationship with closure 104 to form a seal.

In use of prior art package 100, material or objects for containment andpackaging in prior art package 100 were first placed in prior artcanister 102 through opening 129 (FIG. 1B) with prior art closure 104removed as shown in FIG. 1A. After, the material was loaded in prior artcanister 102, prior art closure 104 was telescoped or fitted over andcoupled to prior art canister 102 by snap-fitting, thread-fitting, orother means well known to those of ordinary skill in the art. Moist orliquid materials where often packaged in prior art package 100. Forexample, moistened wipes were packaged within prior art package 100 fordispensing through aperture 118.

FIG. 1B is a partial cross-sectional side view of opened-end portion 112of prior art canister 102 of FIG. 1A after assembly with prior artcanister 102 showing prior art seal 106. FIG. 1C is a close-up view ofthe portion of FIG. 1B shown in dotted line and identified by referencenumber 1C′ showing prior art seal 106 in detail. Referring to FIGS. 1Band 1C together, the exterior surface of opened-end portion 112 of priorart canister 102 defined a sidewall groove 124, configured generally asan annular shaped indentation circumferentially about prior art canister102. Sidewall groove 124 extended radially inwardly from andcircumferentially about the exterior surface of prior art canister 102proximate opened-end portion 112. As shown, the upper edge surface ofsidewall groove 124 forms a sidewall undercut surface 126 that isbeveled downwardly from its exterior to its interior indent.

The interior surface of skirt 116 of prior art closure 104 defined askirt bead surface 128, configured generally as a peripheral flangeprotrusion, sometimes referred to as a bead, adjacent the bottom ofskirt 116. Skirt bead surface 128 extended radially inwardly from andcircumferentially about the interior surface of skirt 116 of prior artclosure 104. Prior art canister 102 was assembled with prior art closure104 by snapping skirt bead surface 128 into sidewall groove 124 wherebyprior art closure 104 was retained on prior art canister 102 by means ofabutting contact of skirt bead surface 128 with sidewall undercutsurface 126 of sidewall groove 124.

In prior art package 100, prior art canister 102 and prior art closure104 were further configured such that, after assembly, sidewall undercutsurface 126 of sidewall groove 124 of prior art canister 102 abuttinglycontacted and cooperated with corresponding skirt bead surface 128 ofprior art closure 104 to form prior art seal 106. Prior art seal 106 wassomewhat effective at avoiding moisture evaporation and in retainingliquid or moisture contained in prior art package 100. Prior art seal106 slowed the loss of the liquid in the form of gaseous water vapor orother volatilized gas at the prior art seal 106 sealing interfacebetween prior art canister 102 and prior art closure 104.

However, in the packaging industry, plastic canisters and closures oftenmay not be accurately sized or may be out-of-round so that cooperatingsurfaces of the closure and canister do not properly and accuratelyseal. In addition, the canister and closure may be manufactured bydifferent entities and the dimensional tolerances may vary greatly. Inaddition, for threaded prior art packages, to facilitate threading ofthe closure relative to the canister, ample thread tolerances are used,which results in axial and radial displacement sufficient to causemisalignment of the cooperating sealing surfaces. All of these variablesand dimensional tolerances make it difficult to ensure a good seal inprior art packages. Poor quality seals resulted in the loss of aninordinate amount of moistening solution added to canister/closureplastic packages thereby requiring high initial moisture loading toavoid product dry-out during storage. High initial moisture loadingadded to over-all product cost.

In the prior art, expensive elastomeric gaskets or “O” rings were oftenused to provide better seals that slowed moisture loss from the package.In addition, well-known but expensive secondary seals, such as inductionseals or heat seals, were often used in prior art packaging to retainmoisture during distribution and in-store or user storage before productuse.

SUMMARY OF THE INVENTION

In accordance with the principles of the present invention, provided isa moisture retention seal that avoids the limitations and expense ofprior art seals. The moisture retention seal includes a first moistureretention component having a plurality of first component sealingsurfaces. Assembled with the first moisture retention component is asecond moisture retention component having a plurality of secondcomponent sealing surfaces. Each first component sealing surfacecooperates with a corresponding one of the second component sealingsurfaces to form a plurality of partial seals. At least one of thepartial seals comprises one or more small projections, sometimesreferred to as micro-bead elements. In one embodiment, first moistureretention component, second moisture retention component, or both areformed from molded thermoplastic material.

When it is said herein that a first surface cooperates with secondsurface to form a seal, it is meant that the first and second surfacesabuttingly contact each other and deform sufficiently due to spatialinterference to form a fluid seal useful in preventing moisture transferacross the seal. When it is said herein that a first sealing surfacecorresponds to a second sealing surface, it is meant that the firstsealing surface and second sealing surface are intended to cooperate toform a moisture retention seal.

Embodiments of a moisture retention seal for use with a package includean opened-ended canister having a plurality of canister sealingsurfaces. Snap-fitted to the canister at its opened-end is a moistureretention closure having a plurality of closure sealing surfaces. Eachcanister sealing surface cooperates with a corresponding one of theclosure sealing surfaces to form a plurality of partial seals. Theclosure may be configured to be slightly smaller in diameter than thecanister, thereby forming an interference fit between the closure andthe canister. The interference may provide a sealing engagement betweenthe closure and the canister at the points of interference along theplurality of cooperating partial seals. At least one of the partialseals includes a micro-bead surface comprising one or more small,inwardly directed, narrowly spaced-apart, micro-bead elements. In oneembodiment, a package that includes a moisture retention seal employsonly molded parts and does not require expensive gaskets or secondaryseals. Accordingly, the moisture retention seal of the present inventionavoids the limitations and expense of prior art seals.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and others will be readily appreciated by theskilled artisan from the following description of illustrativeembodiments when read in conjunction with the accompanying drawings,wherein:

FIG. 1A is an exploded side view of a prior art package that included acylindrically-shaped prior art canister and a cup-shaped prior artclosure;

FIG. 1B is a partial cross-sectional side view of an opened-end portionof the prior art canister of FIG. 1A after assembly with the prior artclosure and showing a prior art seal;

FIG. 1C is a close-up view of the portion of FIG. 1B shown in dottedline and identified by reference number 1C′ showing the prior art sealin detail;

FIG. 2A is a side view of an assembled moisture retention package thatincludes a cylindrical moisture retention canister and a cup-shapedmoisture retention closure coupled to and cooperating with the moistureretention canister to provide an embodiment of a moisture retention sealin accordance with the principles of the present invention;

FIG. 2B is a cross-sectional close-up side view of an opened-end portionof the moisture retention canister that shows a plurality of partialseals after assembly of the moisture retention closure and moistureretention canister;

FIG. 2C is a further close-up view of the portion of FIG. 2B shown indotted line and identified by reference number 2C′ showing a skirtmicro-bead surface in detail;

FIG. 3A is a partial, close-up, top view of the moisture retentionclosure of FIG. 2A showing moisture retention closure ring stand-offsthat provide venting to the moisture retention package of FIG. 2A; and

FIG. 3B is a close-up, partial, cross-sectional side view of moistureretention closure 204 as in FIG. 2B along line 3B′______3B′ of FIG. 3Aalso showing an aperture lid 220 in a closed relationship with themoisture retention closure.

Reference will now be made to the drawings wherein like numerals referto like parts throughout. As used herein, positional terms, such as“bottom” and “top” and the like, and directional terms, such as “up”,“down” and the like, are employed for ease of description in conjunctionwith the drawings. Further, the terms “interior”, “inwardly” and thelike, refer to positions and directions toward the geometric center ofembodiments of the present invention and designated parts thereof. Theterms “exterior”, “outwardly”, and the like, refer to positions anddirections away from the geometric center. None of these terms is meantto indicate that the described components must have a specificorientation except when specifically set forth.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

FIG. 2A is a side view of an assembled moisture retention package 200that includes a cylindrical moisture retention canister 202 and acup-shaped moisture retention closure 204 coupled to and cooperatingwith moisture retention canister 202 to provide an embodiment of amoisture retention seal 206 (FIG. 2B) in accordance with the principlesof the present invention. In one embodiment, moisture retention canister202 includes a bottom 208, generally configured as a disk, and asidewall 210, generally configured as a cylindrical surface, coupled toand extending upwardly from the peripheral edge of bottom 208. Moistureretention canister 202 includes an opened-end portion 212 (FIG. 2B)defining an opening 229 (FIG. 2B) for access from the top of moistureretention canister 202 to material or objects contained therein. In oneembodiment moisture retention canister 202 is integrally formed andcomprises blow-molded or injection-molded thermoplastic material.

In one embodiment, moisture retention closure 204 includes a top 214,generally configured as a disk, and a skirt 216, generally configured asan annular ring or skirt, coupled to and depending downwardly from top214 at the peripheral edge of top 214. Top 214 defines an aperture 218(FIG. 2B) therethrough for extracting material or objects contained inmoisture retention canister 202 from opened-end portion 212 (FIG. 2B).In one embodiment, moisture retention closure 204 is integrally formedby blow-molding or injection-molding and comprises thermoplasticmaterial.

In one embodiment, moisture retention package 200 further includes anaperture lid 220 to close off aperture 218. Aperture lid 220 may becoupled to moisture retention closure 204 by a living hinge 222, bywhich aperture lid 220 pivots with respect to moisture retention closure204 to close off aperture 218 (FIG. 2B) of moisture retention closure204.

FIG. 2B is a cross-sectional close-up side view of opened-end portion212 of moisture retention canister 202 that shows various seals206A-206D after assembly of moisture retention closure 204 and moistureretention canister 202. In illustrative embodiments, the plurality ofseals are partial seals that together can form a complete seal thatadequately seals for anticipated uses. For example, each partial sealmay have a small unsealed area. The combination of these small unsealedareas, however, may present a relatively tortuous path for vapor toescape, thus providing an effective seal for certain applications. Inother embodiments, however, at least one of the seals is a full seal. Insuch case, the other full or partial seals simply are redundant. Ineither case, it is anticipated that redundant seals can help ensure thatat least one is a full seal, or at least the combination of partialseals provides the requisite sealing capabilities. Such use of redundantseals should increase the likelihood that wide error factors andtolerances of some technologies (e.g., blow molding technology) does noteliminate sealing requirements. Unless the context requires otherwise orthe seal is explicitly specified as a partial or full seal, sealsdiscussed herein thus may be either partial or full seals.

Referring to FIG. 2B and directing attention to moisture retentioncanister 202, sidewall 210 comprises a plurality of sealing surfaces226A-226D. As shown in FIG. 2B, sidewall 210 has a first, i.e., anexterior, sidewall surface 211 and a second, i.e., an interior, sidewallsurface 213 opposite exterior sidewall surface 211. Exterior sidewallsurface 211 of moisture retention canister 202 defines sidewall sealingsurfaces that include a sidewall undercut surface 226A, a sidewallupright surface 226B, and a sidewall lip surface 226C. In oneembodiment, sidewall undercut surface 226A, sidewall upright surface226B, and sidewall lip surface 226C, circumferentially extend aboutexterior sidewall surface 211 of moisture retention canister 202.

With reference to sidewall undercut surface 226A, exterior sidewallsurface 211 has sidewall groove 224, configured generally as an annularshaped indentation about moisture retention canister 202 proximateopened-end portion 212. Sidewall groove 224 extends radially inward fromand circumferentially about exterior sidewall surface 211 of moistureretention canister 202. As shown, the upper edge surface of sidewallgroove 224 forms sidewall undercut surface 226A. In one embodiment,sidewall undercut surface 226A slants downwardly from exterior sidewallsurface 211 to its interior indent.

With reference to sidewall upright surface 226B, in one embodiment,sidewall upright surface 226B is above sidewall undercut surface 226Aand is configured generally as an annular ring with a substantiallyflat-face directed outwardly.

With reference to sidewall lip surface 226C, in one embodiment, sidewalllip surface 226C is the top generally horizontal annular surface ofexterior sidewall surface 211 forming a flat-faced upper lip or rim ofmoisture retention canister 202. As described more fully below, sidewalllip surface 226C deflects and pivots downwardly by a deflection angle αfrom its unassembled relaxed horizontal position whenever moistureretention closure 204 is fully assembled and engaged with moistureretention canister 202.

In one embodiment, interior sidewall surface 213 of moisture retentioncanister 202 defines a sidewall bead surface 226D circumferentiallyextending about interior sidewall surface 213. Sidewall bead surface226D is configured generally as a peripheral flange protrusion,sometimes, as described above, referred to as a bead, adjacent and belowsidewall lip surface 226C. Sidewall bead surface 226D extends radiallyinwardly from and circumferentially about interior sidewall surface 213of moisture retention canister 202.

Referring still to FIG. 2B but directing attention to moisture retentionclosure 204, skirt 216 and top 214 of moisture retention closure 204comprise a plurality of sealing surfaces 228A-228D. In one embodiment,skirt 216 of moisture retention closure 204 has a first, i.e., aninterior, skirt surface 215. Skirt interior surface 215 of moistureretention closure 204 defines sidewall sealing surfaces that include askirt bead surface 228A and a skirt micro-bead surface 228B.

With reference to skirt bead surface 228A, in one embodiment, skirt beadsurface 228A is configured as a bead, as described above, adjacent thebottom of skirt 216. Skirt bead surface 228A extends radially inwardlyfrom and circumferentially about skirt interior surface 215 of moistureretention closure 204. When moisture retention package 200 is assembledas described, skirt bead surface 228A of closure 204 cooperates withsidewall undercut surface 226A of canister 202 to form a first partialseal 206A.

With reference to skirt micro-bead surface 228B FIG. 2C is a furtherclose-up view of the portion of FIG. 2B shown in dotted line andidentified by reference number 2C′ showing skirt micro-bead surface 228Bin detail. Referring now to FIGS. 2B and 2C together, in one embodiment,skirt micro-bead surface 228B is configured as one or more, small,narrowly spaced-apart beads, sometimes referred to as micro-beadelements 230, best seen in FIG. 2C. In illustrative embodiments, themicro-bead elements 230 each have bases that are spaced approximatelyone to four base thicknesses apart.

In one embodiment, each micro-bead element 230 of micro-bead surface228B protrudes from skirt interior surface 215 toward the interior ofmoisture retention closure 204 by about 0.013 inches. Adjacentmicro-bead elements 230 are spaced-apart by about 0.030 inches. Themicro-bead elements 230 making up micro-bead surface 228B cooperate withsidewall upright surface 226B to form a second partial seal 206B.Micro-bead surface 228B is particularly effective in retaining moisturewithin moisture retention package 200 when moisture retention canister202 and moisture retention closure 204 are assembled. Each of themicro-bead elements 230 abuttingly contacts sidewall upright surface226B, which together form a tight seal.

In one embodiment, moisture retention closure 204 has an inside diameterat skirt bead surface 228A that is somewhat smaller than moistureretention canister 202 outside diameter at corresponding sidewallundercut surface 226A. Further, moisture retention closure 204 has aninside diameter at skirt micro-bead surface 228B that is somewhatsmaller than moisture retention canister 202 outside diameter atcorresponding sidewall upright surface 226B. Accordingly, as is wellknown to those of ordinary skill in the art, moisture retention closure204 snap-fits to moisture retention canister 202 when assembled as shownin FIG. 2A. When it is said herein that the diameter of a surface of acomponent is somewhat smaller than the diameter of a surface of anothercomponent, it is meant that the diameters differ in length by an amountthat allows cooperation between the components to form spatialinterference therebetween. In one embodiment the inside diameter atskirt bead surface 228A is smaller than the outside diameter of sidewallundercut surface 226A by about 0.014 inches. The inside diameter ofskirt micro-bead surface 228B is smaller than the outside diameter ofsidewall upright surface 226B by about 0.029 inches. The insidediameters must not be so much smaller than the outside diameters suchthat moisture retention closure 204 will not conveniently snap-fit onmoisture retention canister 202.

Referring again to FIG. 2B, further, top 214 of moisture retentionclosure 204 has a first, i.e., an interior, top surface 217. Topinterior surface 217 of moisture retention closure 204 defines sealingsurfaces that include a top protrusion surface 228C and a top undercutsurface 228D. In one embodiment, top protrusion surface 228C and topundercut surface 228D circumferentially extend about interior topsurface 217 of moisture retention closure 204.

With reference to top protrusion surface 228C, in one embodiment, top toprotrusion surface 228C is configured as a tang or projection coupled toand protruding downwardly from top interior surface 217. When moistureretention package 200 is assembled as described, top protrusion surface228C of closure 204 cooperates with sidewall lip surface 226C ofcanister 202 to form a third partial seal 206C. As noted above, sidewalllip surface 226C deflects somewhat downwardly from its unassembledrelaxed position, by deflection angle α, whenever moisture retentionclosure 204 is fully assembled and engaged with moisture retentioncanister 202. The downward deflection of sidewall lip surface 226Cgenerates, at top protrusion surface 228C, an upwardly biasing force onclosure 204, as sidewall lip surface 226C tends to elastically return toits relaxed position. The upwardly biasing force on closure 204 at topprotrusion surface 228C causes sidewall lip surface 226C to moreforcefully engage sidewall lip surface 226C in abutting contact, therebyforming a more effective third partial seal 206C. Further, the upwardlybiasing force on closure 204 causes skirt bead surface 228A to moreforcefully engage undercut surface 226A in abutting contact, therebyforming a more effective first partial seal 206A. In one embodiment,deflection angle α is about 5°.

With reference to top undercut surface 228D, in one embodiment, topundercut surface 228D is configured as a bead extendingcircumferentially about top interior surface 217. When moistureretention canister 202 and moisture retention closure 204 are assembled,top undercut surface 228D cooperates with sidewall bead surface 226D toform a fourth partial seal 206D.

As noted above, in one embodiment, moisture retention closure 204 has aninside diameter at skirt bead surface 228A that is somewhat smaller thanmoisture retention canister 202 outside diameter at correspondingsidewall undercut surface 226A. Further, moisture retention closure 204has an inside diameter at skirt micro-bead surface 228B that is somewhatsmaller than moisture retention canister 202 outside diameter atcorresponding sidewall upright surface 226B. Thus, when assembled asshown in FIG. 2A, moisture retention closure 204 and moisture retentioncanister 202 spatially interfere at first partial seal 206A and secondpartial seal 206B. Moisture retention closure 204 may thus “snap-fit”when assembled to moisture retention canister 202.

To accommodate the spatial interferences at first partial seal 206A andsecond partial seal 206B, opened-end portion 212 of moisture retentioncanister 202 tends to lengthen. The lengthening of opened-end portion212 in turn creates a more effective third partial seal 206C, sincesidewall lip surface 226C of canister 202 is, in turn, more forcefullybiased against and more effectively seated with top protrusion surface228C of closure 204. To accommodate this more forceful biasing at thirdpartial seal 206C, deflection angle α of canister 202 tends to increaseand sidewall bead surface 226D tends to deflect inwardly toward topundercut surface 228D of moisture retention closure 204 thereby, inturn, creating a more effective fourth partial seal 206D.

Thus, it can be seen that the interference created by selecting moistureretention closure 204 with inside diameters at skirt bead surface 228Aand skirt micro-bead surface 228B that are somewhat smaller,respectively, than the outside diameters of sidewall undercut surface226A and sidewall upright surface 226B of moisture retention canister202, produces more effective seals at all the partial seals 206A-206D ofmoisture retention package 200. A more effective overall “system” ofcooperating partial seals is created by selection of the diameters ofmoisture retention canister 202 and moisture retention closure 204. Thevarious elements of the seal “system” flex and deflect as described toaccommodate induced forces thereby creating a more effective overallsealing system.

To determine the effectiveness of moisture retention seal 206,comprising partial seals 206A-206D, moisture retention package 200 wastested and compared to prior art seal 106 (FIG. 1C) of prior art package100 (FIG. 1A) for weight percent moisture loss over time.

Table 1 summarizes the weight percent moisture loss over time formoistened automotive interior protectant wipes stored in moistureretention package 200 as compared to identical wipes stored in prior artpackage 100 (FIG. 1A). As shown, wipes were stored at a constant ambienttemperature of 70° F. and at constant elevated temperatures toaccelerate results. The solution moistening the protectant wipescomprised 23.0 weight percent solids 77.0 weight percent aqueousvolatiles.

As shown in Table 1 cumulative weight percent (wt %) moisture loss formoistened protectant wipes stored in moisture retention package 200 at120° F. amounted to 6.74 wt % loss over a twelve-week period. Bycomparison, protectant wipes stored in prior art package 100 (FIG. 1A)lost 37.87 wt %. Moisture loss for moisture retention package 200amounted to only 17.8% of the moisture loss for prior art package 100(FIG. 1A) under these conditions (120° F., 12 weeks).

Table 2 summarizes the weight percent moisture loss over time formoistened general purpose orange scented cleaning wipes stored inmoisture retention package 200 as compared to identical wipes stored inprior art package 100 (FIG. 1A). The solution moistening the orangescented cleaning wipes comprised 1.2 weight percent solids and 98.8weight percent aqueous volatiles.

As shown in Table 2 cumulative weight percent moisture loss formoistened orange scented cleaning wipes stored in moisture retentionpackage 200 at 120° F. amounted to 8.40 wt % loss over a twelve-weekperiod. By comparison, orange scented cleaning wipes stored in prior artpackage 100 (FIG. 1A) lost 39.41 wt %. Moisture loss for moistureretention package 200 amounted to only 21.3% of the moisture loss forprior art package 100 (FIG. 1A) under these conditions (120° F., 12weeks). When stored at a temperature of 140 F, cumulative weight percentmoisture loss amounted to 13.72 wt % and 69.70 wt % for moistureretention package 200 and prior art package 100 (FIG. 1A), respectively.Moisture loss for moisture retention package 200 amounted to only 19.7%of the moisture loss for prior art package 100 (FIG. 1A) under theseconditions (140° F., 12 weeks).

Table 3 summarizes the weight percent moisture loss over time formoistened leather cleaning wipes stored in moisture retention package200 as compared to identical wipes stored in prior art package 100 (FIG.1A). The solution moistening the leather cleaning wipes comprised 10.7weight percent solids and 89.3 weight percent aqueous volatiles.

As shown in Table 3 cumulative weight percent moisture loss formoistened leather cleaning wipes stored in moisture retention package200 at 100 (FIG. 1A)° F. amounted to 4.56 wt % loss over a twelve-weekperiod. By comparison, leather cleaning wipes stored in prior artpackage 100 (FIG. 1A) lost 20.21 wt %. Moisture loss for moistureretention package 200 amounted to only 22.7% of the moisture loss forprior art package 100 (FIG. 1A) under these conditions (100 (FIG. 1A)°F., 12 weeks). When stored at a temperature of 120 F, cumulative weightpercent moisture loss amounted to 11.08 wt % and 44.96 wt % for moistureretention package 200 and prior art package 100 (FIG. 1A), respectively.Moisture loss for moisture retention package 200 amounted to only 24.6%of the moisture loss for prior art package 100 (FIG. 1A) under theseconditions (120° F., 12 weeks). When stored at a temperature of 140° F.,cumulative weight percent moisture loss amounted to 11.87 wt % and 52.44wt % for moisture retention package 200 and prior art package 100 (FIG.1A), respectively. Moisture loss for moisture retention package 200amounted to only 22.6% of the moisture loss for prior art package 100(FIG. 1A) under these conditions (140° F., 12 weeks).

Moisture Weight Loss Summary

TABLE 1 Protectant Wipes Week 1 Week 2 Week 4 Week 8 Week 12 MoistureRetention Seal Package 70° F. Weight % Lost 0.015 0.17 0.28 0.52 0.78Standard Dev. 0.02 0.02 0.03 0.04 0.05 100° F. Weight % Lost 0.029 0.501.03 2.03 3.06 Standard Dev. 0.04 0.08 0.20 0.38 0.59 120° F. Weight %Lost 0.69 1.16 2.31 4.50 6.74 Standard Dev. 0.017 0.18 0.29 0.61 1.04140° F. Weight % Lost 0.98 1.87 3.68 7.30 10.74 Standard Dev. 0.07 0.320.74 1.29 2.04 Controls (Prior Art Package) 120° F. Weight % Lost 3.506.20 12.59 25.11 37.87 Standard Dev. 0.81 1.37 2.72 5.41 8.30

TABLE 2 Orange Scented Cleaning Wipes Week 1 Week 2 Week 4 Week 8 Week12 Moisture Retention Seal Package 70° F. Weight % Lost 0.16 0.19 0.360.75 1.18 Standard Dev. 0.07 0.07 0.08 0.09 0.11 100° F. Weight % Lost0.43 0.77 1.51 2.95 4.42 Standard Dev. 0.07 0.08 0.11 0.16 0.31 120° F.Weight % Lost 0.85 1.53 2.34 5.43 8.40 Standard Dev. 0.06 1.16 1.19 0.530.82 140° F. Weight % Lost 1.22 2.35 5.17 9.52 13.72 Standard Dev. 0.100.22 0.40 0.78 1.14 Controls (Prior Art Package) 120° F. Weight % Lost3.83 7.16 13.43 25.88 39.41 Standard Dev. 2.85 4.41 6.68 11.44 16.11140° F. Weight % Lost 4.83 10.58 23.92 47.30 69.70 Standard Dev. 3.234.03 −5.54 8.75 10.86

TABLE 3 Leather Cleaning Wipes Week 1 Week 2 Week 4 Week 8 Week 12Moisture Retention Seal Package 70° F. Weight % Lost 0.19 0.22 0.43 0.881.35 Standard Dev. 0.03 0.03 0.05 0.11 0.19 100° F. Weight % Lost 0.340.68 1.43 2.98 4.56 Standard Dev. 0.05 0.05 0.15 0.42 0.69 120° F.Weight % Lost 1.13 1.86 3.82 7.59 11.08 Standard Dev. 0.15 0.11 0.381.19 1.72 140° F. Weight % Lost 1.25 2.26 4.56 8.13 11.87 Standard Dev.0.07 0.12 0.34 0.79 1.10 Controls (Prior Art Package) 100° F. Weight %Lost 2.85 4.21 7.21 13.52 20.21 Standard Dev. 1.29 1.57 2.04 3.09 4.26120° F. Weight % Lost 3.73 6.81 16.52 31.45 44.96 Standard Dev. 4.035.13 10.31 14.96 18.81 140° F. Weight % Lost 5.45 10.17 20.84 37.5852.44 Standard Dev. 3.03 4.51 8.10 14.48 18.58

As described and shown in the above tables, moisture retention package200 employing moisture retention seal 206 in accordance with theprinciples of the present invention is an effective means to preventmoisture loss from plastic moisture retention package 200. The moistureretention effects of partial seals 206A-206D combine to form moistureretention seal 206 that is significantly more effective than prior artseal 106 (FIG. 1C). Moisture loss at elevated storage temperatures frommoisture retention package 200 is only about 17 to 25%, on average, ofthe loss from a prior art package 100 (FIG. 1A). Said another way,moisture retention package 200 has a “moisture loss factor” of about 17%to 25%, where the moisture loss factor is defined as the cumulativeweight percent moisture loss from an improved package, such as moistureretention package 200, divided by the cumulative weight percent moistureloss from prior art package 100 (FIG. 1A) for the same moisteningsolution, under the same conditions over the same time duration. Asdescribed above prior art package 100 comprises a standard prior artsidewall undercut surface 126 and a standard prior art skirt beadsurface 128, well known to those of ordinary skill in the art. Asdescribed, prior art sidewall undercut surface 126 cooperates with priorart skirt bead surface 128 to form prior art seal 106.

As noted above, with reference to FIGS. 2A and 2B, in one embodiment,moisture retention closure 204 includes a top 214, generally configuredas a disk, and a skirt 216, generally configured as an annular ring orskirt, coupled to and depending downwardly from top 214 at theperipheral edge of top 214. Top 214 defines an aperture 218 (FIG. 2B)therethrough for extracting material or objects contained in moistureretention canister 202 from opened-end portion 212 (FIG. 2B). Moistureretention package 200 further includes an aperture lid 220 (FIG. 2A) toclose off aperture 218. Aperture lid 220 may be coupled to moistureretention closure 204 by a living hinge 222, by which aperture lid 220pivots with respect to moisture retention closure 204 to close offaperture 218 (FIG. 2B) of moisture retention closure 204

FIG. 3A is a partial, close-up, top view of the moisture retentionclosure of FIG. 2A showing moisture retention closure ring stand-offs242 that provide venting to moister retention package 200 (FIG. 2B).FIG. 3B is a close-up, partial, cross-sectional side view of themoisture retention closure 204 as in FIG. 2B along line 3B′______3B′ ofFIG. 3A also showing an aperture lid 220 in a closed relationship withmoisture retention closure 204. Referring to FIGS. 3A and 3B together,in one embodiment, moisture retention package 200 (FIG. 2A) may have aventing system. Providing a venting system to moisture retention package200 allows release of excessive pressure buildup within moistureretention package 200 during elevated temperature testing or underexcessive storage temperatures.

In one embodiment, moisture retention closure 204 includes a moistureretention closure sealing ring 234 projecting upwardly from top 214 ofmoisture retention closure 204, similar to closure sealing ring 134 ofprior art closure 104 shown in cross-section in FIG. 1B. Aperture lid220 includes a lid sealing ring 232 (FIG. 3B) near the outer peripheraledge on the bottom surface of lid 220, similar to lid sealing ring 132of prior art closure 104 (FIG. 1B). To form a seal between aperture lid220 (FIG. 3B) and moisture retention closure 204, aperture lid 220 issnap-fitted to moisture retention closure 204. Lid sealing ring 232mates with a moisture retention closure sealing ring 234 formed on top214 of moisture retention closure 204 when aperture lid 220 is pivoted,snap-fitted, and placed in a closed relationship with moisture retentionclosure 204 to form a seal as shown in FIG. 3B. More specifically, a lidring inside surface 238 of lid sealing ring 232 abuttingly contacts andseats against a closure ring outside surface 240 of moisture retentionclosure sealing ring 234.

In this embodiment, to provide a venting system to moisture retentionpackage 200 (FIG. 2A), moisture retention closure sealing ring 234further includes a pair of spaced apart stand-offs 242 configured asprojections that extend radially outward from closure ring outsidesurface 240. Stand-offs 242 define a vent gap 244 through whichexcessive pressure within moisture retention package 200 may be vented.Excessive pressure within moisture retention package occurs whenever thepressure within moisture retention package 200 is more than the pressureneeded to overcome the snap-fit force between aperture lid 220 andmoisture retention closure 204. Said another way, excessive pressurewithin moisture retention package occurs whenever the pressure withinmoisture retention package 200 would cause aperture lid 220 to overcomeits snap-fitting force and “pop” off moisture retention closure 204. Inone embodiment, stand-offs 242 project about 0.0025 inches from closurering outside surface 240 and stand-offs 242 are spaced apart by about0.015 inches. In other embodiments, stand-off 242 may, alternatively,project radially inwardly from lid sealing ring 232.

From this disclosure, one of ordinary skill in the art would recognizethat other conventional materials and fabrication techniques could besubstituted. Also based on this disclosure, the person of ordinary skillin the art would further recognize that the relative proportions of thecomponents illustrated could be varied without departing from the spiritand scope of the invention.

Although the moisture retention package 200 employing an embodiment ofthe moisture retention seal 206 of the present invention shown in thedrawings and described herein as substantially cylindrical, in fact,other structures have surface shaped other than cylindrical couldemployee the moisture retention seal 206 described and shown to achieveimproved moisture retention over conventional prior art seals.Corresponding first and second component surface portions need only beof any suitable shape or cross-section to provide a sealing interfacetherebetween. The substantially cylindrical shape shown herein isbelieved to be advantageous because it may be efficiently andinexpensively manufactured using commonly available molding techniques.

Although the above discussion discloses various exemplary embodiments ofthe invention, it should be apparent that those skilled in the art canmake various modifications that will achieve some of the advantages ofthe invention without departing from the true scope of the invention.

1. A package comprising: a closure having an interior surface and aprotrusion extending from the interior surface; and a canister having aflexible top portion, the protrusion contacting the flexible top portionof the canister, the protrusion normally applying a generally downwardcontact force to at least part of the flexible top portion to form a topseal between the closure and the canister, the protrusion deflecting thepart of the flexible top portion generally downwardly from a restposition, wherein the flexible top portion of the canister is in therest position when not connected with the closure, wherein the closurehas a top undercut surface extending circumferentially about the topinterior surface, and the canister has a sidewall surfacecircumferentially extending about the canister, the top undercut surfacecooperating with the sidewall surface to form an undercut seal.
 2. Thepackage as defined by claim 1 wherein the top undercut surface isradially inward of the protrusion.
 3. The package as defined by claim 1wherein the protrusion is generally annular.